Curable polyester oligomer and a process for producing same

ABSTRACT

A curable polyester oligomer having a molecular weight of between 300 and 10,000 and at least one silyl radical at the side chain or at the end of the molecule, with the silyl radical being represented by the formula: ##STR1## wherein R, R 1  and R 2  represent hydrogen or any monovalent hydrocarbon radical with 1 to 10 carbon atoms, selected from the group consisting of alkyl radical, aryl radical and aralkyl radical; R 3  represents divalent hydrocarbon radical with 0 to 10 carbon atoms, &#34;X&#34; represents any radical selected from the group consisting of halogen, alkoxy, acyloxy, aminoxy, phenoxy, thioalkoxy, and amino radicals; &#34;a&#34; is an integer 0, 1 or 2; and &#34;b&#34; is an integer 0 or 1.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a novel polyester oligomer curable at ambienttemperature and a process for producing same.

There have been attempts to utilize polyester oligomers, as they are, oras an intermediate product, by introducing various functional groups toactivate them, such as for example, as surfactants, paints, adhesives,sealants, printing inks and the like. As for polyester oligomers, it hasalready been known that the properties thereof when used as coatedfilms, such as adhesiveness, strength, oil and solvent resistance, canbe improved by introducing silicone radicals capable of being hydrolyzedinto Si--O--C bond in alkyd resin to be modified.

However, among these priorly known polyester oligomer, there is nonewhich has silyl radicals in the molecule in the manner as shown below informula (1).

The object of this invention is to provide an oligomer which is able tobe easily liquidized without or with only a very small amount of solventand cured at an ambient (i.e. room) temperature when exposed to air, andto provide a curable oligomer having excellent adhesiveness to variouskinds of plastics and glasses. The air usually contains moisture.

The invention encompasses a polyester oligomer having a molecular weightof between 300 and 10,000 and curable at ambient temperature and havingat least one silyl radical in the molecule, with the silyl radical beingrepresented by the formula: ##STR2## wherein R, R₁, and R₂ representhydrogen or any monovalent hydrocarbon radical with 1 to 10 carbon atomsand selected from the group consisting of alkyl radical, aryl radicaland aralkyl radical; R₃ represents any divalent hydrocarbon radical with0 to 10 carbon atoms, "X" represents any radical selected from the groupconsisting of halogen, alkoxy, acyloxy, aminoxy, phenoxy, thioalkoxy,and amino radicals; "a" is an integer 0, 1, or 2; and "b" is an integer0 or 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The polyester oligomer with silyl radicals of this invention, may bereadily obtained by reacting with a polyester oligomer having amolecular weight of between 200 and 8,000 and having C--C double bonds,in the presence of a catalyst comprising one or more transition metalsin the VIII group of the Periodic Chart, such as platinum, a hydrosilanecompound represented by the formula: ##STR3## wherein "R" represents anymonovalent hydrocarbon radical selected from the group consisting ofalkyl radical, aryl radical and aralkyl radical; "X" represents anyradical selected from the group consisting of halogen, alkoxy, acyloxy,aminoxy, phenoxy, thioalkyoxy, and amino radicals; and "a" is an integer0, 1 or 2.

The polyester oligomer having the C--C double bonds which is used inthis invention, can be illustratively prepared in one or more of thefollowing manners:

(I) A polyester* containing hydroxy radicals at the molecular ends ismade to react on allyl chloride in the presence of a base, for example,sodium hydride.

(II) A polyester having hydroxy radicals at the molecular ends, is madeto react on diallyl ester, such as diallyl phthalate, in the presence ofa catalyst, such as toluene sulfonic acid, capable of causing esterinterchange reaction, such as disclosed in Japanese Patent Application(laid-open No. 51-142027).

(III) Dibasic acid and diol are made to condense in the presence ofexcess amount of acid. In the course of, or after, the reactionmonohydric alcohol with C--C double bond is added so as to esterify thecondensate.

(IV) A polyester with acryloyl radicals can be obtained by condensationreaction among diol, dibasic acid and acrylic acid (or methacrylic acid)according to conventional processes.

(V) A condensation reaction is caused between diol and dibasic acid.Prior to the reaction, a small amount of epoxy compound with C--C doublebond is added for a part of diol.

(VI) Alcohol, epoxy compound, and acid anydride are made to react in thepresence of a tertiary amine to produce a polyester. This process hasbeen proposed in Japanese Patent Application 52-159436. Monohydricalcohol and epoxy compound having a C--C double bond, respectively, arepartially or wholely substituted for the alcohol and the epoxy compound.As starting materials to give polyester, dibasic acids, glycols, andpolyhydric alcohols have been used in the above processes (I) through(V). The following are typical compounds which may be illustrativelyused:

Dihydric alcohols (Glycols):

Ethylene glycol, propylene glycol, butane diol, hexamethylene glycol,hydrogenated bispheno A, neopentyl glycol, diethylene glycol,triethylene glycol and dipropylene glycol.

Polyhydric alcohols:

Glycerine, trimethylol methane, trimethylol propane, penta erythritol.

Dicarboxylic acids:

Phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalicacid, hexahydrophthalic acid, tetrachlorophthalic acid, polybutadienedicarboxylic acid, oxalic acid, maronic acid, succinic acid, adipicacid, sebacic acid, malei acid, fumaric acid, cyclopentane dicarboxylicacid.

Polycarboxylic acids:

Trimellitic acid, butane tricarboxylic acid, pyromellitic acid.

Furthermore, carboxylic acid anhydride together with acyl halide can besimilarly used as polycarboxylic acid is. Allyl alcohol and methallylalcohol are examples of monohydric alcohols with the C--C double bondsexplained in methods (III) and (VI) above. Allyl glycidyl ether,glycidyl acrylate and glycidyl methacrylate are examples of epoxycompounds with C--C double bonds described in methods (V) and (VI)hereinabove. When considering how to introduce the C--C double bondsinto the polyester molecule the above examples may be considered. Thesynthesis process (VI) is the most preferable among the six processesbecause with process (VI), the amount of C--C double bond in themolecule and the condensate by-products in the reaction can be readilycontrolled.

As a result of intensive investigations on the process of introducingallylically unsaturated group upon synthesis of polyester oligomer, theinventors have discovered a process for synthesizing a novel polyesteroligomer containing allylically unsaturated group, which process permitsoptionally controlling the content of the allylically unsaturated groupand molecular weight of the oligomer by reacting a system comprising anacid anhydride, epoxy compound and alcohol (as a molecular weightadjusting agent) using a tertiary amine or quanternary ammonium salt asa catalyst. The use of an allyl type alcohol as the alcohol componentenables introduction of allylically unsaturated group and adjustmen- ofmolecular weight at the same time.

That is, the polyester oligomer of the present invention is a novelpolyester oligomer having a molecular weight of 200-8,000, main chain ofwhich substantially comprises a polyester formed by the reaction betweenan acid anhydride, epoxy compound and alcohol, and which has at leastone allylically unsaturated group represented by the following formula:##STR4## wherein R₂ represents a hydrogen atom or a monovalenthydrocarbyl group selected from the group consisting of alkyl group,aryl group, and aralkyl group having 1 to 10 carbon atoms, R₃ representsa divalent hydrocarbyl group having 0 to 10 carbon atoms, and "a"represents an integer 0 or 1 in the side chain or at the terminal end inone molecule.

The term "allylically unsaturated group" as herein used means that grouprepresented by the above formula (3). The term "allyl type alcohol"means the alcohol compound containing ##STR5## as this allylicallyunsaturated group in the molecule.

The polyester oligomer of the present invention is obtained by reactinga system comprising (a) one, or a mixture of two or more, of thecompounds having at least one acid anhydride group of ##STR6## such asphthalic anhydride, di-, tetra- or hexa-hydrophthalic anhydride,succinic anhydride, maleic anhydride, chloromaleic anhydride,pyromellitic anhydride, polyadipic anhydride, polysebacic anhydride,polyisophthalic anhydride, etc; (b) one, or a mixture of two or more, ofcompounds having at least one epoxy group of ##STR7## such as ethyleneoxide, propylene oxide, epichlorohydrin, allyl glycidyl ether, styreneoxide, cyclohexene oxide, Epikote 828 (manufactured by ShellInternational Chemicals Corp), and, as a molecular weight adjustingagent (c) a monohydric or polyhydric alcohol, such as methyl alcohol,ethyl alcohol, propyl alcohol, allyl alcohol, methallyl alcohol, etc.

As a catalyst for the reaction, there may be illustratively used:tertiary amines and quaternary ammonium salts, such as for example, astertiary amines, p,p'-bis(dimethylaminophenol)methane, dimethylaniline,N,N-dimethylpropylamine, dibutylpropylamine, tributylamine,N,N-dimethylbenzylamine; and as quaternary ammonium salts,benzyltrimethylammonium chloride, phenyltributylammonium chloride,cyclohexyltributylammonium sulfate, benzyltrimethylammonium borate.

The reaction temperature is preferably between 70° C. and 150° C. Thereaction may be carried out in an inert solvent having no activehydrogen atoms. In case the viscosity of the reaction system becomesundesirably high, such as n>20, it is preferable to conduct the reactionin the presence of a solvent. Examples of such solvents aretetrahydrofuran, dioxane, toluene, dimethylformamide, etc.

In this reaction, the charging ratio of acid anhydride (a) to epoxycompound (b) can be changed over a wide range without influencing thereaction rate at an initial stage and the molecular weight of theoligomer. Thus, the reaction can be completed in a shorter time byinitially adding (b) in an excess amount by 1 to 3 equivalent weightsbased on (a) or, in the case of using (a) and (b) in equivalent amounts,by further adding (b) at a stage near completion of the reaction. Excess(b) may be removed under reduced pressure.

The molecular weight of the oligomer can be freely controlled by theamount of alcohol (c). Furthermore, the use of an allyl type alcohol,such as allyl alcohol, enables better control of the molecular weightand introduction of allylically unsaturated group at the same time. Thatis, as will be shown in Table 1 in the Examples, it is clear that allylalcohol is introduced into one end of the oligomer.

The content of the allylically unsaturated group in one molecule can beincreased by adding as one of component (b), a compound having bothallylically unsaturated group and epoxy group, such as allyl glycidylether (AGE). As shown in Table 1, the content of the allyl group insynthesized oligomer coincides with the value expected from the amountof added AGE.

For example, the following compound is obtained by reacting an acidanhydride containing one acid anhydride group with an epoxy compoundcontaining one epoxy group in the presence of a monohydric alcohol##STR8## wherein, R₅, R₆ and R₇ represent residues of acid anhydride,epoxy compound and alcohol, respectively, (usually organic groups having1 to 30 carbon atoms), and "n" represents an integer 1 to 50.

When allyl type alcohol is used as the alcohol, R₇ is a grouprepresented by ##STR9## When a compound containing allylicallyunsaturated group is used as part or all of the epoxy compound, R₄ willcontain the allylically unsaturated group of ##STR10## As the compoundscontaining both allylically unsaturated group and epoxy group, methallylglycidyl ether, allylglycidyl ester, etc may be used as well as AGE. Ifallyl alcohol is used in this reaction, R₇ can be shown as ##STR11## Ifallyl glycidyl ether is partly or wholely employed herein, R₆ will be##STR12## In the case of glycidyl acrylate, R₆ becomes ##STR13## andglycidyl methacrylate makes R₆ ##STR14## In the above formula, thealcohol residue is located at the terminal end since monohydric alcoholis used. However, existence of the alcohol residue at the terminal endof the molecule is not always necessary, and, when a polyhydric alcoholis used, it is inserted between the polyester bonds. In the presentinvention, the term "the main chain composed substantially of" meansthat residues derived from other compounds than acid anhydride or epoxycompound may exist in a slight amount, as above illustrated.

The above example illustrates the case of introducing an alcoholresidue, in particular allylically unsaturated group-containing residue,at the one end of the molecule. It is possible to intruduce the residueat both ends. For example, it is possible to once complete the reactionin the system containing excess (a), and then add as component (b) AGEin a necessary amount.

When process (VI) hereinabove, is conducted, the molecular weight of theproduced polyester oligomer can be adjusted to be within the range of200 and 8,000 at will and the number of C--C double bonds to beintroduced can be varied by controlling the amount of alcohol and/orepoxy compound in which the same double bonds are contained.

In using as starting material for such curable composition, the numberof the allylically unsaturated group in the molecule may be one,although two or more are preferable. The olefin equivalent weight(namely, molecular weight per one allylically unsaturated group) ispreferably 200 to 600. In the case of using the composition as a solventfree paint, the polymerization degree (n) is preferably not more than10, since "n" of more than 10 results in high viscosity.

The thusly synthesized allylically unsaturated group containingpolyester oligomer can be used, as such, as a paint composition whichcan be radically cured. Hydrolyzable silicon functional group can beintroduced thereinto according to the process described in Example 8.That is, a silicon group can be introduced into the polyester byreacting the allylically unsaturated group of the allylicallyunsaturated group-containing polyester oligomer with a hydrosiliconcompound in the presence of a group VIII transition metal catalyst.

Among the hydrosilanes represented by formula 3 hereinabove, and whichmay be used in the invention, there are illustrated the following:Tricholoro silane, methyl dichlorosilane, dimethyl chlorosilane, phenyldichlorosilane (silanes halide); trimethoxy silane, triethoxy silane,methyl diethoxy silane, methyldimethoxy silane, phenyl dimethoxy silane(alkoxy silanes); triacetoxy silane, methyl diacetoxy silane, phenyldiacetoxy silane (acyloxy silanes); triaminoxy silane, methyl diaminoxysilane, methyl diaminosilane, etc.

The usable amount of hydrosilane can be varied with the number of C--Cdouble bonds, but the most preferable amount of hydrosilane is theequivalent of 0.5 to 2.0 times as much as the equivalent of thepolyester oligomer. An amount more than this may be used, but the excessis recoverable in the form of unreacted hydrosilane. To be connected,silane halides can be easily employed in the invention, which is highlyreactive and made from inexpensive materials. The polyester oligomerprepared from silane halide rapidly cures at an ambient temperatureproducing hydrogen chloride gas when allowed to stand in air.

Hydrogen chloride may be esthetically undesirable because of itsstinging odor and corrosiveness, which limit the use of silane halide toa narrow list, from that viewpoint. When this is significantly takeninto consideration, it is desirable for halogen radicals to besubstituted for other radicals to be easily hydrolized. Among thoseradicals are alkoxy, acyloxy, aminoxy, phenoxy, thioalkoxy, aminoradicals and the like. In the process for substituting halogen radicalsfor these hydrolizable radicals, the following compounds react onhalogen radicals:

1. methanol, ethanol, 2-methoxy ethanol, sec-butanol, tert-butanol,phenyl (alcohols, or phenols),

2. alkali metal salt of alcohols, or phenols,

3. orthoformic acid, orthoformic acid ester (orthoformic acid alkylate).

In the process for converting halogen radical into acyloxy radicals, thefollowing compound are used:

1. acetic acid, propionic acid, benzoic acid (carboxylic acids),

2. alkali metal salt of carboxylic cid.

Furthermore, in order for halogen radicals to change for aminoxy ones,the following are favorably used to react on halog radicals:

1. N,N-dimethyl hydroxylamine, N,N-diethyl hydroxylamine,N,N-methylphenyl hydroxylamine, N-hydroxypyrolidine (hydroxylamines)

2. alkali metal salts of primary and secondary amines.

In order to substitute halogen radicals for amino radicals, eitherprimary or secondary amines such as N,N-dimethylamine,N,N-methylphenylamine or pyrolidine, or alkali metal salts thereof areto react on halogen radicals.

In order to substitute for thioalkoxy radicals, thioalcohols, such asethylmercaptans, or thiophenols, or alkali metal salts thereof are toreact on halogen radicals.

According to the invention, a catalyst using one or more transitionmetals is required to be present in the step where hydrosilane is madeto react on the C--C double bond. The catalyst may use a transitionmetal complex compound selected from platinum, rhodiu, cobalt, paladiumand nickel complex compounds. See for reference, Journal of the OrganicSynthetic Chemical Society, 28, pp919 (1979).

This hydrosilyl radical introducing reaction can be accomplished at anarbitrary temperature between 50° C. and 150° C. for a period of timefrom one to four hours. In regard to the silyl radicals, not onlyhalogen, but also hydrolizable radicals, such as alkoxy, acyloxy can besubstituted for the other hydrolizable one, for example aminoxy, asdesired. The reaction temperature used, is between 20° C. and 120° C. Insuch case, solvent is not always used for progressing the reaction, butan inert solvent like ethers or hydrocarbons are preferably selected forthis purpose, if necessary.

Among the polyester oligomers to be subjected to the hydrosilylationreaction are thos which contain hydroxy radicals in the molecule. Ifsilane halide is applied in the reaction, the above hydroxy radicalsreact on halogens in the silane halide and a bond between the polyesterand silicon atoms is newly formed by virtue of the presence of alkoxyradicals, and this sometimes follows gelatinization in the course of thereaction. So it is advisable to metnion that the hydrosilylationreaction is to be carried out with the polyester free from hydroxyradicals which has been preliminarily treated with acetic acid anhydrideor the particular silane halide such as trimethyl chlorosilane in whichsuch bond as ##STR15## is not contained. Briefly, the reaction should bemade after unreacted silane halide, acetic acid anhydride, and producedhydrochloric acid or acetic acid are removed.

To illustrate, when the polyester oligomer with C--C double bondssynthesized according to the process (VI) hereinabove, is subjected tothe hydrosilyl radical introducing reaction, the radical represented bythe below formula can be introduced: ##STR16## wherein R, R₁, R₂, R₃, X,"a" and "b" are as defined above. R₄ represents alkyl radicals with 1 to10 carbon atoms.

When allyl glycidyl ether is used as an epoxy component of thepolyester, the radical becomes the following structure: ##STR17## andwhen glycidyl acrylate is used, the radical becomes the followingstructure: ##STR18## and when glycidyl methacrylate is used, thestructure becomes: ##STR19##

The polyester oligomer with silyl radicals of the invention can beprepared in a way other than those discussed above. For example, whenalcohol, epoxy compound, and acid anhydride react on each other in thepresence of tertiary amines, the epoxy compound may be replaced withγ-glyciloxypropyl trimethyoxy silane.

The novel polyester oligomer becomes cured at an ambient temperature bymaking a network structure in itself when exposed to moisture in theair. The curing rate is affected by ambient temperature, relativehumidity, together with the kind of hydrolizable radicals. Accordingly,when preparing the polyester oligomer, it is necessary to take intoconsideration the kind of hydrolizable radicals to be chosen for thegiven purpose.

In order to cure the polyester oligomer, some amount of curingaccelerating agent may be added. For example, one or more of thefollowing can be used: alkyl titanate, metal carboxylate, such as tinoctylate, dibutyl tin laurate, amine, such as dibutylamine-2-hexoate,and acidic catalyst and basic catalysts. The amount of curingaccelerating agent to be added may range from 0.001 to 10 weightpercent, based on the weight of the polyester oligomer.

This oligomer with silyl radicals is excellent in luster and inproducing a film firmly adhering to metal or glass. Thus, this oligomermay be incorporated with coating composites, and used, for example forconstruction materials, aeroplanes, automobiles, electronic parts,sealants and paint composites, and the like. Moreover, it may be usedfor wrapping materials, molding materials, framing materials andsurfacing materials for various kinds of inorganic substances.

Advantageously, the prior art problems are resolved when the polyesteroligomer has one hydrolizable silyl radical in the molecule when thepolyester oligomer is used as a curing composite material. However, apolyester oligomer having more than one silyl radical is more preferablefor imparting surface hardness, heat resistance, boiling waterresistance or solvent resistance, to the cured composite. At the sametime, it is desirable that the equivalent of the silyl radical(molecular weight per one silyl radical) be present between 200 and 750.When the equivalent value is more than 750, the cured film tends to havea reduced resistivity to boiled water and solvent. Besides, it is also acharacteristic of this oligomer that surface hardness, strength, andsolvent resistance of the hardened film can be varied by adding suchpolycondensable monomers as ethylsilicate and its derivatives andhydrolizable oligomers, such as KR 212, KR 213, and the like. (Producedby Shinetsu Chemicals Co., Ltd). Furthermore, into this oligomer can bemixed various kinds of fillers or pigments, among which are includedevery kind of silica, calcium carbonate, magnesium carbonate, titaneoxide, iron oxide, fiberglass, etc.

The appearance of such polyester oligomer having at least onehydrolizable silyl radical is new and the structure thereof can bereadily understood from examination of the processes and examples.

The sole FIGURE depicts the infra-red spectrum of absorption of theoligomer, and will be more fully discussed in the Examples, namely,Example 10. In the FIGURE, the top curve shows the absorption spectrumof the polyester oligomer before the silyl radical is introduced, andthe bottom curve shows that after the same reaction.

The following examples illustrate in greater detail the process andproducts of the invention. It is to be understood that the examples arenot to be considered to be limiting in any manner.

EXAMPLE 1

148 parts (1 mole) of phthalic anhydride, 72 parts (1 mole) of butyleneoxide (BO), 11.6 parts (0.2 mole) of allyl alcohol and 0.5 parts ofdimethylbenzylamine were charged into a 1-liter round bottom flaskequipped with a stirrer, thermometer, nitrogen bubbling tube and coolingtube, and heated to 100° C. A reaction ratio of 90% (calculated fromacid value) was attained in about 3 hours. 7.2 parts of BO was added atthis stage. After further reacting for one hour, the reaction ratioreached 99.5%. Excess BO was removed to obtain colorless and viscouspolyester oligomer. The resulting oligomer had a molecular weight of1150, an olefin equivalent weight of 1148 and a hydroxyl equivalent of1160. The word part whenever used herein means part by weight, unlessotherwise stated.

EXAMPLES 2, 3 and 4

Allyl alcohol, allyl glycidyl ether (AGE) and BO were reacted with thereaction ratios shown in Table 1. Other conditions other than thecharging ratio were the same as in Example 1. As the amount of allylalcohol decreased, the hydroxyl equivalent weight increased, the valuesof which coincided with the values expected from the structure shown inthe formula.

The GPC (gel mermeation chromatography) of the product of Example 3showed that the molecular weight distribution (Mu/Mn) was as narrow as1.1. As shown in the FIGURE, infrared spectrum thereof showedabsorptions of hydroxyl group at 3550 cm⁻¹ and 3450 cm⁻¹, ester carbonylgroup absorption at 1720 cm⁻¹ and carbon to carbon double bondabsorption at 1645 cm⁻¹.

EXAMPLE 5

When the amount of allyl glycidyl ether was increased as in Table 1, toreact in the same manner as in Example 1, there was also obtainpolyester oligomers having molecular weights and olefin equivalentweights substantially as theoretically calculated.

EXAMPLE 6

148 parts (1 mole) of phthalic anhydride, 46.4 parts (0.8 mole) ofpropylene oxide (PO), 22.8 parts (0.2 mole) of allyl glycidyl ether,11.6 parts (0.2 mole) of allyl alcohol and 0.5 parts ofdimethylbenzylamine were charged in a 1-liter metallic autoclave, andreacted at 100° C. After 3 hours, 46 parts of PO was added and thereaction was further conducted for one hour to obtain an acid value of0.5. Then, excess PO was removed to obtain a colorless and viscousoligomer having a molecular weight of 1120 and olefin equivalent weightof 573.

EXAMPLE 7

9.5 parts (0.093 mole) of acetic anhydride was added to 100 parts of thepolyester obtained in Example 5, and after reacting at 120° C. for 2hours, acetic acid and acetic anhydride were removed under reducedpressure. Absorption of hydroxy group in the resulting oligomer almostcompletely disappeared.

                                      TABLE 1                                     __________________________________________________________________________    Phthalic         Allyl                                                        Anhydride                                                                              BO  AGE alcohol   Olefin                                                                              Hydroxy                                      (molar   (molar                                                                            (molar                                                                            (molar                                                                            Molecular                                                                           Equivalent                                                                          Equivalent                                   ratio)   ratio)                                                                            ratio)                                                                            ratio)                                                                            Weight.sup.(1)                                                                      weight.sup. (2)                                                                     Weight.sup.(3)                               __________________________________________________________________________    Ex. 2                                                                            1     0.6 0.4 0.4 640(650)                                                                            320(325)                                                                            660(650)                                     Ex. 3                                                                            1     0.8 0.2 0.2 1190(1200)                                                                          580(600)                                                                            1185(1200)                                   Ex. 4                                                                            1     0.9 0.1 0.1 2100(2300)                                                                          1130(1150)                                                                          2200(2300)                                   Ex. 1                                                                            1     1.0 0   0.2 1150(1158)                                                                          1148(1158)                                                                          1160(1158)                                   Ex. 5                                                                            1     0.4 0.6 0.2 1200(1284)                                                                          330(321)                                                                            1210(1284)                                   __________________________________________________________________________     NOTES:                                                                        .sup.(1) Measured according to vapor pressure method (V.P.O.)                 .sup.(2) Measured according to iodine value test, JIS K0070                   .sup.(3) Measured according to hydroxy value test, JIS K0070             

EXAMPLE 8

22.2 parts of the polyester obtained in Example 7, 0.0035 part ofchloroplatinic acid and 8.65 parts of methyldichlorosilane were reactedat 80° C. for 3 hours. After completion of the reaction, unreactedmethyldichlorosilane was removed udner reduced pressure. 17.6 parts ofmethanol was added to the residue, and stirred for one hour at roomtemperature to remove the generated hydrogen chloride gas, and theexcess methanol, under reduced pressure. Further, a slight amount ofpropylene oxide was added to make the system neutral. 2 parts ofdibutyltin laurate was added to this system. When this system was curedin the atmosphere, the system became tack-free after one hour, and thepencil hardness became 5H after 3 days.

EXAMPLE 9

A liquid polyester with molecular weight of 500, the molecular ends ofwhich are attached acryloyl radicals (produced by Toa SyntheticChemicals Co, Ltd, under the trade name "ARONIX"M6100) was put in anitrogen replaced flask by 100 parts. After adding 55.2 parts of methyldichlrosilane and 0.01 part of ethyleneplatinum complex thereto, themixture was allowed to react on each other at 100° C. for 3 hours withstirring in a stream of nitrogen. When the reaction was over, unreactedmethyl dichlorosilane was removed under reduced pressure and 85 parts ofmethyl orthoformate was added at 60° C. with stirring. The reactionsystem showed neutrality after 30 minutes continuous removal of formingmethyl chloride. Light yellowish liquid was produced after removingvolatile components (methyl chloride, methyl formate, methylorthoformate) under reduced pressure.

The infrared absorption spectrum showe complete disappearance of the1630 cm⁻¹ and the 1615 cm⁻¹ bands attributed to acryloyl radical. Theliquid with 2 parts of dibutyl tin maleate became free from stickinessafter 3 hours from being spread on a tin plate and 7 days later itbecame as hard as HB pencil lead.

REFERENTIAL EXAMPLE 1

A mixture comprising 148 parts (1 mole) phthalic acid anhydride, 34.8parts (0.6 mole) propylene oxide, 45.6 parts (0.4 mole) allyl glycidylether, 11.6 parts (0.2 mole) allyl alcohol, and 0.5 parts dimethylbenzylamine were put into a 1 liter metal autoclave and subjected toreaction at 100° C. with stirring. Three hours later there was addedagain 4.6 parts propylene oxide in order to continue the reaction forone hour. After the acid value reached 0.5, colorless viscous olgomerwas obtained by removing excess polyprylene oxide. The molecular weightof the oligomer was 1200.

To 100 parts of this polyester oligomer was further added 10.2 parts(0.1 mole) of acetic acid anhydride, and the mixture was made to reactat 120° C. for 2 hours. Then, excess acetic acid anhydride was removedunder reduced pressure. The oligomer had a molecular weight of 1250, anolefin equivalent of 429, and an acetyl value of 70%.

EXAMPLE 10

A mixture was prepared by adding to 100 parts of the polyestersynthesized in Referential Example 1, 0.012 part of chloroplatinic acid(isopropanol:tetrahydrofuran=1:10) and 32.2 parts methyl dichlorosilane,and reacted at 80° C. for 4 hours with stirring. After termination ofthe reaction, unreacted methyl dichlorosilane was removed under reducedpressure. To this was further added 30 parts of methanol and stirringwas continued for 1 hour at room temperature to reove generated hydrogenchloride gas and excess methanol, by evacuating the atmosphere. Then, asmall amount of propylene oxide was put therein to make the reactionsystem neutral. Light yellowish sticky oligomer was found after removalof volatile components. The sole FIGURE shows the infrared absorptionspectrum of the oligomer. It was proven that 1645 cm⁻¹ absorption bandassigned to olefin component completely disappears and the silyl value(determined by iodine titration) is 98%. The oligomeric substance, with2 parts of dibutyl tin laurate, was spread over a glass plate. Theoligomer became free from tack and showed a hardness which was the sameas 2H pencil lead.

EXAMPLE 11

A mixture was prepared by adding to 100 parts of the polyester obtainedin referential example 1, 0.012 part of chloroplatinic acid and 29.6parts of methyl dimethoxysilane was made to react at 80° C. for 3 hourswith stirring. Unreacted methyl dimethoxysilane was removed underreduced pressure. The resulting polyester oligomer showed a silyl valueof 90%. One hour after coating a glass plate with the polyester,including 2 parts dibutyl tin laurate, the polyester lost stickiness andbecame a solid which was as hard as 2H pencil lead.

REFERENTIAL EXAMPLES 2-5.

A mixture comprising phthalic acid anhydride, butylene oxide, allylglycidyl ether, and allyl alcohol was subjected to reaction in the samewas as mentioned in referential example 1. As a result of this, apolyester oligomer, the ends of which sllyl radicals are combined with,was obtained. The molecular weight and olefin equivalent are show inTable 2.

EXAMPLES 12,13,14,15.

To each of the C--C double bonds contained in the polyester oligomers inreferential examples 2 to 5, were added methyl dimethoxysilane of 1.2times equivalent and chloroplatinic acid of 1×10⁻⁴ time equivalent, thenthe mixture was allowed to react at 80° C. for 4 hours. The silyl valueand the film properties of the obtained polyester are shown in Table 2.

EXAMPLE 16

A mixture was prepared by adding to 100 parts of a polyester with allylradicals at the molecular ends, 0.009 part of chloroplatinic acid and 28parts of trichlorosilane, and reacted at 80° C. for 4 hours withstirring. After completion of the reaction, unreacted trichlorosilanewas removed under reduced pressure. 33 parts of methanol was added tothis system and stirring was continued at room temperature for 1 hourunder reduced pressure in order to remove the formed hydrochloric gasand the excess methanol. A small amount of propylene oxide was mixedthereinto to neutralize the reaction system. After volatile matters wereremoved, light yellowish sticky oligomer was left behind. The silylvalue, together with the film properties of the silyl radical containingpolyester, are shown in Table 2. It was roven that the reaction tointroduction of silyl radicals into the polyester molecule unexpectedlysubstantially improves the adhesiveness, impact strength and variousconditions of the process.

The foregoing, and Table 2 following this paragraph, are illustrative ofthe principles of the invention. Numerous modifications and extensionthereof would be apparent to the worker skilled in the art. All suchmodifications and extension are to be considered to be within the spiritand scope of this invention.

                                      TABLE 2                                     __________________________________________________________________________                       Polyester                                                  Polyester with allyl radicals                                                                    with Silyl                                                                          Polyester film Properties 4*                         at the ends         radicals                                                                           Pencil    Impact strength                                                                       Boiling                            Ref    Molecular                                                                           Olefin equi-                                                                        Silyl lead Ericksen                                                                           3/8 500 g                                                                             water                              ex.    weight 1*                                                                           valent 2*                                                                           value(%)3*                                                                          hardness                                                                           value                                                                              × 50 cm 5*                                                                      test 6*                            __________________________________________________________________________    Ex. 12                                                                            2  1280  340   95    4H   >9 (mm)                                                                            No crack                                                                              ⊚                   Ex. 13                                                                            3  1240  440   93    3H   >9   was observed                                                                          ⊚                   Ex. 14                                                                            4  1200  580   94    2H   >9   on the  ⊚                   Ex. 15                                                                            5  3150  980   89    4H   >9   cured film                                                                            Δ                            Ex. 16                                                                            4  1200  580   94    2H   >9           ⊚                   __________________________________________________________________________     NOTES:                                                                        1* Determined by the measurement of vapour pressure depression.               2* According to the iodine test in JIS K0070                                  3* Estimated from the formula:                                                ##STR20##                                                                     4* The polyester mixed with 2 parts dibutyl tin laurate was estimated         after 7 day drying by the use of abrasive mild steel #320                     5* Dupont Impact Strength (3/8, 500g × 50 cm)                           6* Boiling water test for two hours; no change ⊚slight         gloss reduction Δ-                                                 

What is claimed is:
 1. A curable polyester oligomer having a molecularweight of between 300 and 10,000, and at least one silyl radicat at theside chain or at the end of the molecule, the silyl radical beingrepresented by the following formula: ##STR21## wherein R, R₁ and R₂represent hydrogen or any monovalent hydrocarbon radical with 1 to 10carbon atoms and selected from the group consisting of alkyl radical,aryl radical and aralkyl radical, R₃ represents divalent hydrocarbonradical with 0 to 10 carbon atoms, "X" represents any radical selectedfrom the group consisting of halogen, alkoxy, acyloxy, aminoxy, phenoxy,thioalkoxy, and amino radicals, "a" is an integer of 0, 1 or 2 and "b"is an interger of 0 or
 1. 2. Polyester oligomer of claim 1, wherein themolecular weight of each of said silyl radical is between 200 and 750.3. The polyester oligomer of claim 1, or claim 2, wherein said silylradical is at least at the side chain and at the ends of the molecule.4. The polyester oligomer of claim 1 wherein said oligomer is admixedwith a filler.
 5. The polyester oligomer of claim 1, wherein saidoligomer is subjected to curing.
 6. A process for producing curablepolyester oligomer, characterized by making a compound comprisedsubstantially of polyester oligomer having a molecular weight of between200 and 8,000 and at least one C--C double bond at the side chain or atthe end of a molecule, to react with a hydrosilane compound representedby the formula: ##STR22## wherein R represents any monovalenthydrocarbon radical having 1 to 10 carbon atoms and selected from thegroup consisting of alkyl radical, aryl radical and aralkyl radical, "X"represents any radical selected from the group consisting of halogenalkoxy, acyloxy, aminoxy, phenoxy, thioalkoxy and amino radicals, and"a" is an integer of 0, 1, or 2, at a temperature between 50° C. and150° C.
 7. The process of claim 6, wherein the reaction is allowed toprogress in the presence of a catalyst comprising a transition metal inGroup VIII of the Periodic Chart.
 8. The process of claim 6, wherein acompound comprising substantially polyester is the polymerizationproduct of an acid anhydride with epoxy compound in the presence ofalcohol.
 9. The process of claim 8, wherein said alcohol is an allylictype alcohol represented by the following formula: ##STR23##
 10. Theprocess of claim 7, wherein a part of or all of said epoxy compoundcontains both epoxy group and allylically unsaturated group of theformula: ##STR24##